Ch 6 Parasternal Measurements Flashcards
Measurements are most accurate using what type of resolution?
Axial (along length of beam)
Most measurements are obtained during what part of the cardiac cycle?
-End diastole
-End systole
Are most measurements taken when the valves are open or closed?
Closed
List 4 ways in which we can identify that our image is in end diastole?
-Largest LV volume
-Smallest atrial volume
-At R wave on ECG
-Frame at MV closure (m/c)
(IVS is thinner, LV is relaxed)
List 4 ways in which we can identify that our image is in end systole?
-Smallest LV volume
-Largest atrial volume
-At end T wave on ECG
-Frame at AoV closure (m/c)
(IVS is thicker)
How do our measurements affect pt care + their outcomes?
Accuracy = repeatability
Incorrect measurements = potentially incorrect diagnosis/treatment
How can we avoid over or under estimating our measurements?
Imagine an imaginary line cutting through out structure in SAG, our measurement must be perpendicular to this line to be accurate (if not then we will be oblique)
What 2 things can help us get more accurate measurements in PLAX?
-Heel/toe probe to get LV flat
-Angle to get rid of pap muscles + chords
Should we measure each chamber/structure in our image with the same angle?
No, each has a different angle unique to that structure
Why do we measure structures in echocardiography?
-To assess for changes in heart size due to pathologies
-To monitor cardiac abnormalities
We are learning measurements + reference values off of what company?
American Society of Echocardiography
How do we measure the IVSd?
-Vertically from RV side of IVS to LV side of IVS
-Don’t include RV trabeculations
-Be perpendicular to long axis of LV, just past MV leaflet tips
-Measure in end diastole (when all valves closed)
What is the pitfall when measuring the IVSd?
Accidentally including the RV trabeculations in our measurement
What is normal IVSd measurement?
M: 0.6-1.0cm
F: 0.6-0.9cm
If we go to measure the IVSd and we notice a sigmoid septum, how do we measure this?
-Avoid measuring the bulge of the IVS
-Measure just after bulge
What is a sigmoid septum caused by?
Age related changes of the heart (is a thick IVS)
In cardiac, do we tend to measure the thickest area of a structure or an area with more continuous size?
Area of more continuous size, to take a representation of the average
(think it is the opposite of general u/s)
How do we measure the LVIDd?
-Vertically from endocardium of IVS to endocardium of LVPW
-Perpendicular to long axis of LV
-Measured in same frame as IVSd
What measurement provides the 1st measurement of our Teicholtz ejection fraction calculation?
LVIDd
Normal value of LVIDd?
M: 4.2-5.8cm
F: 3.8-5.2cm
What is a pitfall when measuring the LVIDd?
-Not measuring passed pap muscle/chord + including it in our measurement (including these assumes that these structures exists circumferentially)
-Not being perpendicular to our imaginary axis line (being 90 degrees to it is most accurate)
How to measure the PWd?
-Vertically from endocardium of LVPW to epicardium
-Measure in same frame as IVSd + LVIDd
Normal value of PWd?
M: 0.6-1.0cm
F: 0.6-0.9cm
(same as IVSd)
How to measure the LVIDs?
-Perpendicular to long axis of LV
-Measure at end systole (same beat as end diastolic measurement of LVIDd)
-Vertically from endocardium of IVS to endocardium of PW
What measurement provides the 2nd measurement of our Teicholtz ejection fraction calculation?
LVIDs
Normal value of LVIDs?
M: 2.5-4.0cm
F: 2.2-3.5cm
Normal EF range?
M: 52-72%
F: 54-74%
Why do females have a higher EF range?
B/c they have a larger difference b/w the LVIDd + LVIDs
What is ejection fraction by teicholz?
Estimate of LV systolic function via % of blood volume ejected with each occurrence of systole (during each cardiac cycle)
What is fractional shortening?
-Rough estimate of LV systolic function
-Measures contractility + inward motion of endocardium
Is fractional shortening still used in clinical practice?
Rarely
Normal range of fractional shortening?
25-45%
(typically half of EF)
How to measure the AoR?
-Measure at end diastole in front of closed valve
-Zoom into AO to optimize
-Leading edge to leading edge (outer to inner)
-Perpendicular to wall of AoR
Other names for AoR measurement?
-Sinus of Valsalva
-AO diameter
Normal value of AoR?
M: 3.1-3.7cm
F: 2.7-3.3cm
Pitfall of AoR measurement?
Measuring too close to AoV annulus, this will underestimate this parameter
How to measure LVOT?
-Zoom in on AO to optimize
-Measure at mid systole with valve open
-Inner edge to inner edge
-0.5cm up to 1cm away from AoV
-Measure perpendicular to LVOT
What is the 1st measurement required for AoV calculation?
LVOT
What is the only measurement we take with the valve open?
LVOT
Normal value for LVOT?
1.8-2.2cm
How to measure asc AO?
-Acquire in HPLAX (decrease depth to only asc AO)
-Measure in end diastole
-Leading edge to leading edge (outer to inner) in most distal portion we can see
-Measurement is perpendicular to plane of AO
Normal value of Asc AO?
M: 2.6-3.4cm
F: 2.3-3.1cm
Is the ascending AO measurement done at the most proximal or distal part seen in HPLAX?
Distal
How to measure the LAs?
-At end systole with valves closed
-Vertically from leading edge of the posterior wall of AoR to leading edge of posterior wall of LA wall
-Use sinus of valsalva as a guide of where to measure
-Measure perpendicular to plane of LA
Normal value of LAs?
M: 3.0-4.0cm
F: 2.7-3.8cm
How to measure the RVOT?
-At PSAX AoV typically
-End diastole
-Inner to inner
-All valves closed
How to measure the RVOT proximally + distally?
Prox: anterior RV wall to AoV (to the top of the screen)
Dist: anterior RV wall to AoV, just proximal to PV
(to the right side of screen)
Normal value of RVOT proximal measurement?
2.1-3.5cm
Normal value of RVOT distal measurement?
1.7-2.7cm
LV mass is a risk factor + strong predictor of what?
Cardiovascular events
List 3 different methods for calculating LV mass?
-2D linear
-M mode
-3DE
(all convert volume to mass by multiplying volume of myocardium by myocardial density (1.05g/mL))
LV mass formula?
LV mass = 1.05 (total volume - chamber volume)
LV mass varies depending on what factors?
-Gender
-Age
-Body size
-Obesity
-Region in world
LV mass is higher in men or women?
Men (also increases with body size)
LV mass measurements are indexed to what?
BSA
LV mass normal value?
M: 49-115 g/m^2
F: 43-95 g/m^2
What is relative wall thickness?
Simpler measure of ventricular geometry with pt’s with hypertrophy of myocardium
What does relative wall thickness show?
Relationship b/w wall thickness + cavity size
Normal value of relative wall thickness?
0.32-0.42
How is relative wall thickness calculated?
By doubling the dimension of the PW + dividing by the LV diastolic dimension
RWT = (2 x PWd) / LVd
What is normal geometry?
Normal LV mass + RWT
What is concentric hypertrophy?
-Increased LV mass + RWT
What is eccentric hypertrophy?
Increased LV mass + normal RWT
What is concentric remodeling?
Normal LV mass + increased RWT
Give an example of concentric hypertrophy?
Aortic stenosis (small chamber + thick walls), causing LV pressure overload
Give an example of eccentric hypertrophy?
Aortic regurgitation (dilated chamber with normal wall thickness, increased total weight of ventricle), causing chronic volume overload
Give an example of concentric remodelling?
Hypertensive heart disease
